FluxFlow.Components.Observability 1.1.0

FluxFlow.Components.Observability

Reusable observer components for FluxFlow.

Nodes

The package emits neutral contracts only. Hosts decide whether those entries or snapshots become app logs, dashboards, files, telemetry, or test assertions.

Counter

{
  "type": "flow.counter",
  "inputType": "message",
  "name": "received",
  "predicate": "value.Enabled",
  "engine": "default",
  "boundedCapacity": 128
}

flow.counter emits FlowCounterSnapshot values with count, rejected count, last observed timestamp, name, and input type. When no predicate is configured, all inputs are counted.

Logger

{
  "type": "flow.logger",
  "inputType": "message",
  "level": "Information",
  "category": "workflow",
  "messageTemplate": "Observed {kind} item #{sequence}",
  "attributeSelectors": [ "kind", "size" ],
  "boundedCapacity": 128
}

flow.logger emits FlowLogEntry values. Hosts register selector functions for custom attributes. Built-in selectors input and value return the original input.

Metrics

{
  "type": "flow.metrics",
  "inputType": "message",
  "name": "received",
  "sizeSelector": "payloadBytes",
  "boundedCapacity": 128
}

flow.metrics emits FlowMetricSnapshot values with total count, current rate, average rate, last observed timestamp, and optional size values. Size selectors can return numeric values, strings, byte arrays, or collections.

Registration

registry.RegisterObservabilityComponents(options => options
    .UseClock(observabilityClock)
    .RegisterType<MyMessage>("message")
    .UseValueSelector<MyMessage>("kind", (message, _) => message.Kind)
    .UseValueSelector<MyMessage>("payloadBytes", (message, _) => message.Payload.Length));

UseClock(...) is optional. Without it, observer nodes use the default system clock. Supplying a clock lets hosts and tests make log entry timestamps, counter snapshots, metrics snapshots, and rate calculations deterministic.

Register an expression engine only when using counter predicates:

registry.RegisterObservabilityComponents(options => options
    .UseExpressionEngine(expressionEngine)
    .RegisterType<MyMessage>("message"));

Design Metadata

This package exposes a package-owned IComponentDesignMetadataProvider for its node types. Hosts can compose it through ComponentDesignMetadataCatalog to populate palettes, editors, validation views, and documentation without duplicating package descriptors.

Composition Guidance

Use this package as one part of a host-composed graph. See Component Composition for recommended host boundaries, package boundaries, and extraction timing.